DTC P0128-00: Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature) [10/2015 - 08/2016]: Procedure

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CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0128-00)

Connect the Techstream to the DLC3.
Turn the engine switch on (IG).
Turn the Techstream on.
Enter the following menus: Powertrain / Engine / Trouble Codes.

Read the DTCs.

Powertrain > Engine > Trouble Codes

Result

Result	Proceed to
DTC P0128-00 is output	A
DTC P0128-00 and other DTCs are output	B

HINT:

If any DTCs other than P0128-00 are output, troubleshoot those DTCs first.

Result:

GO TO DTC CHART. Refer to DIAGNOSTIC TROUBLE CODE CHART [10/2015 - 08/2016]

Result:

See step 2

CHECK ENGINE COOLING SYSTEM

Check for defects in the engine cooling system that might cause the system to be too cold, such as abnormal cooling fan operation or any modifications.

Result

Proceed to
OK
NG

Result:

REPAIR OR REPLACE ENGINE COOLING SYSTEM

Result:

See step 3

INSPECT THERMOSTAT

Inspect the thermostat (thermostat opening temperature).

Refer to INSPECTION [10/2015 - ]

Result

Proceed to
OK
NG

Result:

REPLACE THERMOSTAT. Refer to REMOVAL [10/2015 - ]

Result:

See step 4

INSPECT ENGINE COOLANT TEMPERATURE SENSOR

Inspect the engine coolant temperature sensor.

Refer to INSPECTION [10/2015 - ]

HINT:

Perform "Inspection After Repair" after replacing the engine coolant temperature sensor.

Refer to INITIALIZATION [10/2015 - 10/2018]

Result

Proceed to
OK
NG

Result:

REPLACE ECM. Refer to REMOVAL [10/2015 - ]

Result:

REPLACE ENGINE COOLANT TEMPERATURE SENSOR. Refer to REMOVAL [10/2015 - ]